Lighting Period Setting Method, Display Panel Driving Method, Backlight Driving Method, Lighting Condition Setting Device, Semiconductor Device, Display Panel and Electronic Equipment

1. A lighting period setting method for a display panel which permits control of a peak luminance level for a field period by controlling a total lighting period length which is the sum of all lighting periods in the field period, the lighting period setting method comprising the steps of, for a given field period: calculating a total average luminance level based on image data by averaging the luminance levels of pixels in N frames of an image to be displayed, wherein at least one of the N frames includes the frame to be displayed during the given field period; setting the total lighting period length for the given field period based on the total average luminance level; selecting a light emission mode for the given field period from a plurality of light emission modes based on the image data and the total average luminance level; determining setting conditions for the light emission mode; and setting, for the given field period, the number, arrangement and lengths of lighting periods according to the setting conditions and the total lighting period length so as to provide the peak luminance level, wherein the plurality of light emission modes includes: a still image mode; a motion image emphasis mode; a balanced mode; and a flicker emphasis mode, wherein the frame to be displayed during the given field period comprises a plurality of blocks, each block including a plurality of pixels, the method further comprising the steps of: calculating a block average luminance level for each block by averaging the luminance levels of the pixels of the respective block; detecting any blocks that have a block average luminance level greater than a predetermined luminance threshold value; detecting any regions that are larger than a predetermined size threshold, wherein the regions consist of contiguous blocks that have been detected to have a block average luminance level greater than the predetermined luminance threshold value; and detecting a flicker component level in the frame to be displayed during the given field period based on the size of the largest detected region and the number of detected regions; and wherein, when the flicker emphasis mode is selected, the setting conditions are based on the detected flicker component level.

2. The lighting period setting method of claim 1 , further comprising: driving a pixel array section so as to provide the set lighting periods.

3. The lighting period setting method of claim 1 , further comprising: driving a backlight so as to provide the set lighting periods.

4. A lighting condition setting device comprising: a luminance level calculation portion configured to calculate a total average luminance level for a given field period based on input image data by averaging the luminance levels of pixels in N frames of an image to be displayed, wherein at least one of the N frames includes the frame to be displayed during the given field period; a total lighting period length setting unit configured to set the total lighting period length for the given field period based on the total average luminance level a light emission mode selecting unit configured to select a light emission mode for the given field period from a plurality of light emission modes based on the image data and the total average luminance level; and a lighting period setting unit configured to determine setting conditions for the light emission mode and set the number, arrangement and lengths of lighting periods per field period according to the setting conditions and the total lighting period length so as to provide a peak luminance level which is set according to the input image data, wherein the plurality of light emission modes includes: a still image mode; a motion image emphasis mode; a balanced mode; and a flicker emphasis mode, wherein the frame to be displayed during the given field period comprises a plurality of blocks, each block including a plurality of pixels, and the lighting period setting unit is configured to: calculate a block average luminance level for each block by averaging the luminance levels of the pixels of the respective block; detect any blocks that have a block average luminance level greater than a predetermined luminance threshold value; detect any regions that are larger than a predetermined size threshold, wherein the regions consist of contiguous blocks that have been detected to have a block average luminance level greater than the predetermined luminance threshold value; and detect a flicker component level in the frame to be displayed during the given field period based on the size of the largest detected region and the number of detected regions; and wherein, when the flicker emphasis mode is selected, the lighting period setting unit determines the setting conditions based on the detected flicker component level.

5. The lighting condition setting device of claim 4 , wherein the device is a semiconductor device.

6. A display panel whose peak luminance level is variably controlled by controlling the total lighting period length which is the sum of all lighting periods per field period, the display panel comprising: a pixel array section having a pixel structure appropriate for active matrix driving; a luminance level calculation portion configured to calculate a total average luminance level for a given field period based on input image data by averaging the luminance levels of pixels in N frames of an image to be displayed, wherein at least one of the N frames includes the frame to be displayed during the given field period; a total lighting period length setting unit configured to set the total lighting period length for the given field period based on the total average luminance level a light emission mode selecting unit configured to select a light emission mode for the given field period from a plurality of light emission modes based on the image data and the total average luminance level; a lighting period setting unit configured to determine setting conditions for the light emission mode and set the number, arrangement and lengths of lighting periods per field period according to the setting conditions and the total lighting period length so as to provide a peak luminance level which is set according to the input image data; and a panel drive section configured to drive the pixel array section so as to provide the set lighting periods, wherein the plurality of light emission modes includes: a still image mode; a motion image emphasis mode; a balanced mode; and a flicker emphasis mode, wherein the frame to be displayed during the given field period comprises a plurality of blocks, each block including a plurality of pixels, and the lighting period setting unit is configured to: calculate a block average luminance level for each block by averaging the luminance levels of the pixels of the respective block; detect any blocks that have a block average luminance level greater than a predetermined luminance threshold value; detect any regions that are larger than a predetermined size threshold, wherein the regions consist of contiguous blocks that have been detected to have a block average luminance level greater than the predetermined luminance threshold value; and detect a flicker component level in the frame to be displayed during the given field period based on the size of the largest detected region and the number of detected regions; and wherein, when the flicker emphasis mode is selected, the lighting period setting unit determines the setting conditions based on the detected flicker component level.

7. The display panel of claim 6 , wherein the pixel array section has a pixel structure in which electro luminescence elements are arranged in a matrix form, and the panel drive section sets the lighting periods of the electro luminescence elements.

8. The display panel of claim 6 , further comprising: a backlight drive section configured to drive a backlight source so as to provide the set period length.

9. Electronic equipment comprising: a pixel array section having a pixel structure appropriate for active matrix driving, the pixel array section whose peak luminance level is variably controlled by controlling the total lighting period length which is the sum of all lighting periods per field period; a luminance level calculation portion configured to calculate a total average luminance level for a given field period based on input image data by averaging the luminance levels of pixels in N frames of an image to be displayed, wherein at least one of the N frames includes the frame to be displayed during the given field period; a total lighting period length setting unit configured to set the total lighting period length for the given field period based on the total average luminance level a light emission mode selecting unit configured to select a light emission mode for the given field period from a plurality of light emission modes based on the image data and the total average luminance level; and a lighting period setting unit configured to determine setting conditions for the light emission mode and set the number, arrangement and lengths of lighting periods per field period according to the setting conditions and the total lighting period length so as to provide a peak luminance level which is set according to the input image data; a panel drive section configured to drive the pixel array section so as to provide the set lighting periods; a system control section; and an operation input section for the system control section, wherein the plurality of light emission modes includes: a still image mode; a motion image emphasis mode; a balanced mode; and a flicker emphasis mode, wherein the frame to be displayed during the given field period comprises a plurality of blocks, each block including a plurality of pixels, and the lighting period setting unit is configured to: calculate a block average luminance level for each block by averaging the luminance levels of the pixels of the respective block; detect any blocks that have a block average luminance level greater than a predetermined luminance threshold value; detect any regions that are larger than a predetermined size threshold, wherein the regions consist of contiguous blocks that have been detected to have a block average luminance level greater than the predetermined luminance threshold value; and detect a flicker component level in the frame to be displayed during the given field period based on the size of the largest detected region and the number of detected regions; and wherein, when the flicker emphasis mode is selected, the lighting period setting unit determines the setting conditions based on the detected flicker component level.

10. The electronic equipment of claim 9 further comprising: a backlight source whose peak luminance level is varied by controlling the total lighting period length which is the sum of all lighting periods per field period; and a backlight drive section configured to drive the backlight source so as to provide the set period length.

11. A lighting period setting method for a display panel which permits control of a peak luminance level for a field period by controlling a total lighting period length which is the sum of all lighting periods in the field period, the lighting period setting method comprising the steps of, for a given field period: calculating a total average luminance level based on image data by averaging the luminance levels of pixels in N frames of an image to be displayed, wherein at least one of the N frames includes the frame to be displayed during the given field period; setting the total lighting period length for the given field period based on the total average luminance level; selecting a light emission mode for the given field period from a plurality of light emission modes based on the image data and the total average luminance level; determining setting conditions for the light emission mode; setting, for the given field period, the number, arrangement and lengths of lighting periods according to the setting conditions and the total lighting period length so as to provide the peak luminance level; and detecting a motion amount of the image to be displayed, based on the image signal data, wherein the plurality of light emission modes includes: a still image mode; a motion image emphasis mode; a balanced mode; and a flicker emphasis mode, wherein the still image mode is selected when the detected motion amount is less than a first predetermined value, and wherein, when the detected motion amount is greater than the first predetermined value: the motion image emphasis mode is selected when the calculated average luminance is less than a second predetermined value, the balanced mode is selected when the calculated average luminance is greater than the second predetermined value and less than a third predetermined value, the third predetermined value being greater than the second predetermined value, and the flicker emphasis mode is selected when the calculated average luminance is greater than the third predetermined value, wherein the setting conditions are determined such that: when the motion image emphasis mode is selected, the lighting periods are arranged within the given field period within a first range, the length of which is less than a first maximum value that is less than the length of the given field period; when the balanced mode is selected, the lighting periods are arranged within the given field period within a second range, the length of which equals a second maximum value that is greater than the first maximum value and less than the length of the given field period; and when the flicker emphasis mode is selected, the lighting periods are arranged within the given field period within a third range, the length of which is less than a third maximum value that is greater than the second maximum value and less than the length of the given field period, wherein the motion emphasis mode comprises a plurality of motion emphasis setting levels and the flicker emphasis mode comprises a plurality of flicker emphasis setting levels, the method further comprising: detecting a flicker component level; when the motion emphasis mode has been selected, selecting a motion emphasis setting level from the plurality of motion emphasis setting levels according to the detected motion amount; and when the flicker emphasis mode has been selected, selecting a flicker emphasis setting level from the plurality of flicker emphasis setting levels according to the detected flicker component level; wherein the setting conditions are determined according to the selected motion emphasis setting level in the motion emphasis mode and according to the selected flicker emphasis setting level in the flicker emphasis mode.

12. The lighting period setting method of claim 11 , wherein the frame to be displayed during the given field period comprises a plurality of blocks, each block including a plurality of pixels, the method further comprising the steps of: calculating a block average luminance level for each block by averaging the luminance levels of the pixels of the respective block; detecting any blocks that have a block average luminance level greater than a predetermined luminance threshold value; detecting any regions that are larger than a predetermined size threshold, wherein the regions consist of contiguous blocks that have been detected to have a block average luminance level greater than the predetermined luminance threshold value; and detecting the flicker component level based on at least one of the size of the largest detected region and the number of detected regions.

13. The lighting period setting method of claim 11 , wherein the setting conditions are determined such that: when the still image mode is selected, when the total lighting period length is less than a still image threshold value, there is only one lighting period in the given field period, beginning at the start of the given field period, and when the total lighting period length is greater than or equal to the still image threshold value, there are two lighting periods of equal length in the given field period, one of which begins at the start of the given field period and the other of which starts at 50% of the given field period.

14. The lighting period setting method of claim 11 , wherein the setting conditions are determined such that when the motion image emphasis mode is selected, there is only one lighting period in the given field period when a motion emphasis setting level corresponding to a largest detected motion amount is selected, and there are M>1 lighting periods in the given field period when a motion emphasis setting level corresponding to a detected motion amount smaller than the largest detected motion amount is selected, wherein the M lighting periods are arranged symmetrically about the center of the first range with no-light periods in between each lighting period, the length of each of the M lighting periods is set such that a first fixed symmetric ratio of lengths is maintained and the length of each lighting period closer to the center of the first range is greater than the lengths of any lighting period further from the center of the first range, and the length of each no-light period that is interposed between lighting periods of the given field period is set such that a second fixed symmetric ratio of lengths is maintained and the length of each no-light period closer to the center of the first range is less than the lengths of any no-light period further from the center of the first range; when the balanced mode is selected, there are M>1 lighting periods in the given field period, wherein the M lighting periods are arranged symmetrically about the center of the second range with no-light periods in between each lighting period, the length of each of the M lighting periods is set such that a third fixed symmetric ratio of lengths is maintained and the length of each lighting period closer to the center of the second range is greater than the lengths of any lighting period further from the center of the second range, and the length of each no-light period that is interposed between lighting periods of the given field are equal; and when the flicker emphasis mode is selected, there are M>1 lighting periods in the given field period, wherein the M lighting periods are arranged symmetrically about the center of the third range with no-light periods in between each lighting period, the length of each of the M lighting periods is set such that a fourth fixed symmetric ratio of lengths is maintained and the length of each lighting period closer to the center of the third range is greater than the lengths of any lighting period further from the center of the third range, and the length of each no-light period that is interposed between lighting periods of the given field period is set such that a fifth fixed symmetric ratio of lengths is maintained and the length of each no-light period closer to the center of the third range is greater than or equal to the lengths of any no-light period further from the center of the first range; wherein a largest term of the first ratio is larger than or equal to a largest term of the third ratio, which is larger than a largest term of the fourth ratio, such that for any given total lighting period, the longest lighting period of the motion image emphasis mode is longer than or equal to the longest lighting period of the balanced mode, which is longer than the longest lighting period of the flicker emphasis mode.

15. The lighting period setting method of claim 14 , wherein the setting conditions are determined such that: the length of the first range is larger when a motion emphasis setting level corresponding to a comparatively small detected motion amount is set than the length of the first range when a motion emphasis setting level corresponding to a comparatively large detected motion amount is set; and the length of the third range is larger when a flicker emphasis setting level corresponding to a comparatively large detected flicker component level is set than the length of the third range when a flicker emphasis setting level corresponding to a comparatively small detected flicker component level is set.

16. The lighting period setting method of claim 14 , wherein, whenever there are more than one lighting periods in the given field period, the first lighting period begins at the beginning of the corresponding range and the second lighting period ends at the end of the corresponding range.

17. The lighting period setting method of claim 11 , wherein the first maximum value is 75% of the given field period, the second maximum value is 85% of the given field period, and the third maximum value is 90% of the given field period.

18. The lighting period setting method of claim 1 , wherein the total lighting period length is set such that the magnitude of the total lighting period length is inversely related to the magnitude of the total average luminance level.